- You are currently viewing DISCO3.CO.UK as a guest - Register to take part or Log In
Roel
Member Since: 16 Aug 2008
Location: home
Posts: 1215
  
|
Andrew,
Quote:Only if you keep the car stable. The DSC will still engage even though its off (lets say 70% off) especially if the car detects sideways movement. For example driving a rutted track that has a bend at the bottom of a steep climb.
Does it really takes power away or do you loose momentum as it activates the brakes to keep the car stable. I noticed the brakes to come on but didn't notice it was taking away power with DSC off. Roel
1997 Camel Trophy Disco ex-P101JWK (traded it for a Britains 42101)
1984 90 TD5
2005 G4 Disco 3 BN55WPT
Also member of club MTR
and Club Faultmate
Interested in my 4x4 history see my website: www.mudmachine.webklik.nl
Sorry it's in Dutch and with google translator it gets funny.
|
 17th Mar 2009 9:39 pm |
|
|
AndrewS
Tarquin of the Desert
Member Since: 06 May 2005
Location: Y...... because I can
Posts: 10438
|
It backs the power off  In the Beginning there was nothing, which exploded.
|
| 17th Mar 2009 9:43 pm |
|
|
simon
Member Since: 11 Jan 2005
Location: Shropshire
Posts: 18296
 
|
It does both to varying degrees depending on how likely it thinks you will fall off the road.
|
| 17th Mar 2009 11:09 pm |
|
|
redjelly5000
Member Since: 18 Jul 2008
Location: Rugby
Posts: 473
 
|
Sorry to revive this old thread folks, but I still have a big problem with this and it's worse than ever.
Just to recap, my DSC seems to be false triggering, and even on bone dry roads at low speeds when there is no chance that the system is needed. I found that it seems to be fine when I am driving alone, but as soon as I add a load, like the family for example, (2 adults, 4 children) or if I add the trailer, then the problem starts.
I have had over a grands worth of work done recently, some of which I thought may have been affecting the problem. Both front wheel bearings, rear upper suspension arm bushes both sides, 4 wheel computer alignment, and new discs and pads all round. I suspected that the bushes and bearings especially might have been affecting it, given the loose play in the suspension, but the problem is still there and getting worse.
I can't think what could be causing this, but it is driving me crazy and the car is starting to get quite hard to drive, as the DSC is kicking in so very often. I think the biggest clue is the fact that the problem is worse when there are passengers in the care or a load in or on the car. I thought maybe the shocks maybe the problem, but they look ok, and my specialist (Cambrian 4x4 Farm) thinks they look ok too. Today he recalibrated the steering column sensor on advice from the tech guys at autologic. This made no difference. He called them to see what they though could be the problem. We checked the OBD and there were no related faults.
Does anyone have any advice to get my pride and joy running properly again? What could it be? D3 TDV6 HSE 2008 Buckingham Blue (current)
D3 TDV6 HSE 2009 Zermatt Silver (previous)
D3 TDV6 HSE 2005 Maya Gold (previous)
D2 TD5 ES 1999 (previous)
Defender TD5 swb hard top 2005 (previous)
Defender 300tdi swb hard top 1994 (previous)
|
| 20th Jul 2009 11:34 pm |
|
|
Bushwanderer
Member Since: 27 Nov 2007
Location: Northern Rivers, NSW, Australia
Posts: 2050
|
Hi redjelly,
Apologies if I'm stating the "bloody obvious", but are all wheels/tyres the same size & make?
Have you replaced your wheel with the slow leak with the spare?
Best Wishes,
Peter The Bearded Dragon
|
| 21st Jul 2009 6:10 am |
|
|
GaryEss
Member Since: 27 Apr 2009
Location: midlands
Posts: 42
|
I have cut and pasted this from a previous thread re: DSC operation.
DSC is not too sophisticated - it's only really concerned with yaw rate (sensor under centre console) and steering angle (Sensor on column). It's main function is to quell unwanted oversteer or understeer. It does this by using the ABS system to individually brake one wheel on one side only (on the rear to control understeer, on the front to control oversteer).
It looks at steering angle and rate and wheel speeds , "decides" where the driver is attempting to go and if the yaw rate of the vehicle does not concur it will brake the wheel on one side to "pull" the vehicle toward the desired direction. In extreme case DSC will also limit engine torque output, and adjust transfer case and rear e diff locking torque if necessary.
The same warning light in the IPK will also illuminate when the the traction control is active. This is different to DSC (though the function is integrated into the same control unit). This looks for differences in wheel speed. Up to a certain speed it will brake the spinning wheel to maintain grip- no doubt you may have seen this during off road excursions. Over a certain speed threshold it will limit engine torque only (no wheel braking)when wheel speed differences are detected.
Does your car have the same size , make and load rated tyres all round? Can you try a substitute set and retest? Any difference in rolling radius can cause the VDM to falsely operate especially during cornering.
If these are all correct and identical then check the vehicle history. If the Steering angle sensor has been calibrated with the column turned off centre or if a significant adjustment to the geometry has been needed then it may require re calibration again. Obviously any fault with the yaw or SAS could also cause system faults.
If there are any external issues that cause excessive yaw rate when loaded (suspension, wheels, driving style) then the DSC will activate, but in these type of circumstances it is working correctly and doing it's job.
Finally when DSC is switched "off" it can still activate if extreme circumstances are detected
I hope this information helps with your troubleshooting of the system.
|
| 21st Jul 2009 7:32 am |
|
|
AndrewS
Tarquin of the Desert
Member Since: 06 May 2005
Location: Y...... because I can
Posts: 10438
|
Tyre Pressures or faulty level sensor. In the Beginning there was nothing, which exploded.
|
| 21st Jul 2009 8:11 am |
|
|
redjelly5000
Member Since: 18 Jul 2008
Location: Rugby
Posts: 473
|
Hi All, Many thanks for the replies so far. Firstly, tyres and wheel sizes and load ratings are all correct and the tyres are all matching Scorpion Zeros 19". The two rears don't have much left on them but are legal, and the fronts were new about 5k ago. I don't have any leaks and the pressures are all set correctly.
I had the steering sensor recalibrated to centre only yesterday by my specialist on his autologic system, but this has made no difference. I was certain that the DSC was what was being triggered as the power is lost at the same time as the ABS triggers, but if you say this happens with the traction control too, then it could be either. I have never noticed power loss with the traction control in off road situations before, so I assumed it to be the DSC issue. Also, this is never happening in a loss of traction situation, but always in a bend, and often at perfectly normal speeds on dry roads that I know well, and have driven in this same car a thousand times. I have driven the same corners in the same car in the wet and in the snow and never had this problem previously.
I haven't tried substituting a set of wheels/tyres yet but I may be able to do that if I beg a set from someone. Otherwise, should I start by replacing the yaw sensor under the dash then? Or would I be wise to start changing the wheel sensors or the ride height sensors? I simply have to get to the bottom of this, as it's making my car undriveable! My specialist is great but even he has no clue what is causing this.
Please keep the suggestions and advice coming. Thanks. D3 TDV6 HSE 2008 Buckingham Blue (current)
D3 TDV6 HSE 2009 Zermatt Silver (previous)
D3 TDV6 HSE 2005 Maya Gold (previous)
D2 TD5 ES 1999 (previous)
Defender TD5 swb hard top 2005 (previous)
Defender 300tdi swb hard top 1994 (previous)
|
| 21st Jul 2009 9:20 am |
|
|
GaryEss
Member Since: 27 Apr 2009
Location: midlands
Posts: 42
|
The previous thread on DSC, where I cut and pasted the above from needed to change the steering angle sensor to cure their issue - if this sensor is faulty just doing a calibration will not fix it, Calibrating the sensor just "tells" the system the straight ahead postion. The height sensors have no bearing on DSC activation, so do not change these. The ONLY sensors that the VDM is using to determine whether the DSC should be activated are steering angle/ rate, yaw sensor pack and wheel speed (to cross check with the SAS that the vehicle is travelling in a straight line
HOWEVER- I would caution against attempting to fix your issue by replacing parts on a trial and error basis as this could become very expensive.
I do not know what the capabilities of your specialists diagnostic equipment are but IDS (dealer diagnostic tool) can read live sensor values which the technician can use to analyse the issue. I would recommend this as the next step, either through a suitably equipped and knowledgeable independent or a main agent.
Please also don't forget that the vehicle could actually have an separate issue (suspension etc)that is actually making the vehicle unstable even at a low speed when laden thus the DSC could be working as necessary to prevent a loss of control.
I don't know how to post a link to another thread but if you search my posts you will be able to find the previous DSC thread.
good luck,
|
| 21st Jul 2009 5:50 pm |
|
|
ad15
Member Since: 14 Dec 2008
Location: up that tree
Posts: 4866
|
Quote:If this is the case take it for a drive and keep an eye on the display
i'd keep an eye on the road if i were you, you might drive into something..  one wife.......livid
|
| 21st Jul 2009 5:54 pm |
|
|
redjelly5000
Member Since: 18 Jul 2008
Location: Rugby
Posts: 473
|
Thanks for all the excellent advice Gary, I must admit that I have suspected that the DSC is working as it should, and that there is another underlying issue causing it to trigger. I thought it might have been the play in the front wheel bearings or the bushes on the rer suspension arms, but now having had those fixed and the problem still there, I don't know what to make of it. The rest of the suspension appears to be ok.
I tried switching off the DSC tody and it ran fine. Of course I need to try using a different set of tyres, but after that I'll have to ask my specialist how much he wants to get involved, and what his Autologic kit is capable of. D3 TDV6 HSE 2008 Buckingham Blue (current)
D3 TDV6 HSE 2009 Zermatt Silver (previous)
D3 TDV6 HSE 2005 Maya Gold (previous)
D2 TD5 ES 1999 (previous)
Defender TD5 swb hard top 2005 (previous)
Defender 300tdi swb hard top 1994 (previous)
|
| 21st Jul 2009 11:13 pm |
|
|
AndrewS
Tarquin of the Desert
Member Since: 06 May 2005
Location: Y...... because I can
Posts: 10438
|
Contact 10forcash In the Beginning there was nothing, which exploded.
|
| 22nd Jul 2009 11:30 am |
|
|
JR
Member Since: 23 Jul 2009
Location: Cape Town
Posts: 76
 
|
redjelly5000 wrote:I'll have to ask my specialist how much he wants to get involved, and what his Autologic kit is capable of.
Hi Red.
Once you've spoken to him, please let us know what he says.
I've recently had a similar experience (wife and two kids in the car - turn through a right hander and the DSC kicked in for a split second).
However, a day or so later, I found I had a slow puncture on the left front - and since the repair (plug) it's not happened again.
Cheers
JR
|
| 23rd Jul 2009 8:39 pm |
|
|
redjelly5000
Member Since: 18 Jul 2008
Location: Rugby
Posts: 473
|
It seems that I may have solved the problem finally (with your help THANKS  )
I think it was all down to tyre pressures in the rear tyres. It seems that I was checking them with a duff gauge, which was reading 10 psi higher than the actual pressure. When I got hold of a decent gauge, I found both rears to be only 28psi !! so after inflating them to the correct pressures, I can't say that I have had the problem since.
It does explain why the problem was worse under load conditions I suppose! I never really suspected the gauge to be wrong, as the tyres looked fine, not soft at all, but then 28 isn't that far from where the front ones normally sit, so I guess they would look ok compared with them.
Thanks everyone for all your help. I'm glad it wasn't someting more expensive.... D3 TDV6 HSE 2008 Buckingham Blue (current)
D3 TDV6 HSE 2009 Zermatt Silver (previous)
D3 TDV6 HSE 2005 Maya Gold (previous)
D2 TD5 ES 1999 (previous)
Defender TD5 swb hard top 2005 (previous)
Defender 300tdi swb hard top 1994 (previous)
|
| 30th Jul 2009 3:57 pm |
|
|
|
Posting Rules
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
|
DISCO3.CO.UK Copyright © 2004-2024 Futuranet Ltd & Martin Lewis
|
|
